This application relates to the field of digital cartography, and more particularly to classifying a region in a land use and land cover map and/or updating a classification of the region using postal records.
The Land Use and Land Cover (LULC) map of the United States, produced by the United States Geological Survey (USGS), classifies areas on a map according to the use and/or cover of the areas. At least nine major classifications may be used, including urban, agricultural, and forest. The map may also provide related information about political units and federal land ownership.
The LULC map has numerous applications, including producing cartographic products, base map plotting, radio propagation modeling, and various kinds of spatial analyses. Land use classifications important to radio propagation modeling, for example, include transportation, industrial, water, forest, built-up residential and commercial classifications. The map data may also be combined with other geographically referenced data for automated analysis in support of numerous decision making processes. These, and many other applications, attest to the usefulness of maps that deal with LULC.
Because of obsolescence, however, in the last several years the LULC map has not been as useful as it might otherwise be. The existing USGS LULC map for the US was created in the 1970s using data that may be even older. Since then, advances in the US economy, notably in transportation and construction, have had a great impact on infrastructure and population distribution. Hence, significant changes in LULC have occurred during the last twenty years, a period in which up-to-date and accurate LULC information continued to be a key requirement for many applications listed above.
The USGS LULC information may be updated through satellite images, usually at scales smaller than 1:60,000. In particular, a basic source of land use data is NASA high-altitude aerial photographs. In addition, National High-Altitude Photography program photographs may be used to obtain information about the use and cover of land in various geographic regions.
Updating LULC maps from such images, however, has at least four disadvantages: (i) it is difficult to distinguish accurately in satellite images between commercial and residential built-up categories, (ii) it is expensive, (iii) satellites must be launched into space using equipment that is prone to failures and delay, and (iv) satellites may fall into disrepair while in orbit and may not be available for geographic imaging. Thus, there exists a need for systems and methods capable of updating land use and land cover map data that distinguish accurately between commercial and residential areas, are less expensive than satellite imagery, and are reliable.
The systems and methods described herein help to overcome the aforementioned problems pertaining to accuracy, expense, and reliability of updating an LULC map. In one embodiment of the present invention, a method is provided wherein ZIP+4 data and their corresponding classifications, available from the United States Postal Service, may be used to accurately and reliably classify and/or update regions on the LULC map as residential or commercial. Such use of the ZIP+4 data may also be less costly than that associated with the traditional use of satellite images.
In particular, a method for classifying a region on a map is presented hereinafter that includes identifying a particular region on a map, the region being associated with a particular geographic position. The method further includes obtaining two sets of postal records, such as ZIP+4 codes, each record in the first set having a corresponding geographic position, and each record in the second set having a corresponding classification. The first set contains a particular postal record to which the particular geographic position corresponds, and the second set also contains this particular postal record to which a classification corresponds. The geographic position may be specified by a latitude and longitude, while the classification may include a highrise, commercial, and/or residential classification. Subsequently, the particular region may then be classified with the particular classification.
A method for updating a classification of a region on a map is also presented below. The method includes obtaining a first set of postal records, each record having a corresponding classification, and obtaining a second set of postal records, each record having a corresponding geographic position. The method further includes identifying a match between a postal record in the first set and a postal record in the second set, and then using the geographic position corresponding to the postal record in the second set identified in the match to locate a region to be updated on the map. The classification of the region on the map may then be updated by substituting the classification of the region to be updated with the classification corresponding to the postal record in the first set identified in the match.
Also presented below is a method for classifying a region on a map. The method includes obtaining a first set containing at least one member, wherein each member of the first set includes a postal record and a corresponding geographic position. The method also includes obtaining a second set containing at least one member, wherein each member of the second set includes a postal record and a corresponding classification. From these two sets, a third set may be constructed containing at least one member, wherein each member of the third set includes a geographic position from the first set and an associated classification from the second set; in this last step, a classification is associated with a geographic position if both the classification and the geographic position correspond to a common postal record. Subsequently, a region located at a geographic position from the third set may be classified with the associated classification.
A method for updating land use and land cover data that provide a land classification of a region on a map is also presented below. The method includes obtaining a postal record, associated with the region, and a corresponding land classification. The postal record may include a ZIP+4 code, and the land classification may include a highrise, commercial, or residential classification. The method further includes updating the data by replacing the land classification of the region on the map with the corresponding land classification.
The step of updating the data may further include obtaining a first bitmap that associates the region with the land classification, constructing a second bitmap that associates the region with the corresponding land classification, and overlaying the second bitmap on the first bitmap to update the data. In addition, the step of updating the data may further include dilating, and filtering the data to more clearly indicate the classification of the region.
Also presented below is a system for updating land use and land cover data that provide a land classification of a region on a map. The system may include a database having a postal record, associated with the region, and a corresponding land classification. The system may further include a processor, coupled to the database, for updating the data by replacing the land classification of the region on the map with the corresponding land classification.